Posted by chadlupkes on 02/18/07 16:19

Good discussion.

There are a few other options for validating an email address that
I've found. Here are some links:

http://www.smartwebby.com/DHTML/email_validation.asp

http://www.4guysfromrolla.com/webtech/091998-1.shtml

http://homepage.ntlworld.com/kayseycarvey/jss3p7.html

http://javascript.about.com/od/completescripts/a/email.htm

http://www.w3schools.com/js/js_form_validation.asp

And there's more:

http://www.google.com/search?hl=en&q=validate+email+address+javascript

Thanks for the input! I think I'll go with something a little more
mainstream.

Chad

On Feb 18, 5:04 am, "Richard Cornford" <Rich...@litotes.demon.co.uk>
wrote:
> pcx99 wrote:
> > -Lost wrote:
> >> chadlupkes wrote:
> <snip>
> >>> <?if(preg_match("/MSIE 5.0;/", $_SERVER['HTTP_USER_AGENT']))
> >>> // this is IE 5.0
> >>> {?>
> <snip>
> >> I swear this looks like PHP and JavaScript.
> <snip>
> > You swear right! It sends one block of code to the browser
> > if the client is MSIE version 5 and another for all other
> > versions.
>
> It sends one block of code if the User Agent header contains the
> character sequence "MSIE 5.0" and the other if it does not. That has
> nothing to do with whether the browser is IE 5 or not, as the User Agent
> header is not specified as being a source of information and many
> browsers are known to spoof IE's UA headers (and so some will spoof IE 5
> directly, or include the character sequence "MSIE 5.0").
>
> > Probably to work around some bug or another in IE.
>
> It is an irrational attempt to compensate for the level of regular
> expression support. It suffers from assuming non-standard regular
> expression syntax is available in all browsers that are not IE 5 (or
> spoofing IE 5 in some way).
>
> <snip>> This script will need to be placed on a server with php to work
> > properly. It can be altered to function without the need for php.
>
> > function parseemail(str) {
> > str = trim(str);
> > if (navigator.userAgent.indexOf('MSIE 5.0')>0) {
>
> ^^
> For equivalence with the irrational PHP above that should be; greater or
> equal to 0, or greater than -1.
>
> > if(str.search(/\w+@[\w\W]+\.[a-z]{3}/) == -1) {
> > window.alert("Please enter a valid email address");
> > return true;
> > } else {
> > if(str.search(/^[\w\-\.]+[@][\w\-]+(?:\.[\w\-]+)+$/) == -1) {
> > window.alert("Please enter a valid email address");
> > return true;
> > }
> > }
> > }
> >}
>
> > I didn't test the function so it will probably implode, or
> > explode but at least it gets a little closer to being liked
> > by explorer.
>
> <snip>
>
> The User Agent header (and so the navigator.userAgent string) is not
> specified as being a source of information, and so should not be used as
> one. There is no relationship, real or implied, between the contents of a
> User Agent header and the level of regular expression support on a
> browser. Regular expression support in JScript is independent of the
> browser version. If the first regular expression is ever acceptable there
> is no reason why it should not always be acceptable. Neither regular
> expression seems to be a discriminator of a "valid email address" (though
> the first is much worse than the second).
>
> A bad idea moved from PHP to the client is not a step forward.
>
> Richard.

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